Zizioulas on apophaticism

. . . the apophatic theology of this period [of Dionysius and Maximus the Confessor] by no means implies a theological agnosticism, if carefully studied in its essential aims. The principal object of this theology is to remove the question of truth and knowledge from the domain of Greek theories of ontology in order to situate it within that of love and communion. That apophatic theology founds itself on love is something so evident as to be the necessary key to its understanding and assessment. The perspectives offered by an approach to being through love, as arrived at by the mystical and ascetic theologians of the period, led by another route to the same conclusion that the eucharistic and trinitarian approaches of the previous period reached: it is only through an identification with communion that truth can be reconciled with ontology.

John D. Zizioulas, Being as Communion. Studies in Personhood and the Church. London, DLT, 1985 (2004) 92.